I

Az is a letter of the Russian alphabet, formerly the Old Russian alphabet. However, after Peter the Great's reforms, it was subject to change, and some letters from the old alphabet disappeared. Az was very close to all of them, so he had a very difficult time coping with the loss. Also, since it is the first, and therefore the main, letter, he can't help but blame himself for what happened. Even though he knows in his head that he couldn't do anything, he still can't accept the fact that the situation was beyond his control.
He is terrified of a repeat of the situation and tries to avoid any mention of what happened.
He's angry at the other letters in the alphabet for "so quickly" forgetting about his comrades. However, he doesn't openly say anything to them. (More than 300 years have passed.)
He was already very anxious, but after what happened, he became practically panicky. He tries to act as if everything is fine, but in reality, he still hasn't accepted what happened, as he hasn't talked about it with anyone. He really wants to be pitied, but he's afraid to show weakness in front of anyone.

Choleric

As the first letter of the alphabet, Az considers himself obligated to maintain order and peace among the Symbolars. Admittedly, he's not very successful at it.

Carries a pocket knife with him.

Sweet, feeling your importance when you obey him, violence.

Those who can stand up for themselves. Collectors, too cheerful, quiet and shy people. Feminine men. Masculine women. Animals. When no one listens to him. Children. Concerts and holidays after 10:00 pm. Summer, winter. Buses, sand, milk, robots, the ocean, lemons, castles, paintings…. And so on down the list.

Sweet, even cloying. We're addicted to caffeine.

All except the one he likes. Even if he hasn't tried it yet.

Rude. Cruel even towards those he likes. Impulsive, often acting rather childish. Picky, always with a sour expression. Little pleases him. Cynical, arrogant, and bitchy. Sarcasm.
Strict. He's very anxious, even panicky, and depressed inside, yet full of energy. If you get to know him better, you'll discover other characteristics: irritating, clingy, talkative...

Reading, learning the Russian alphabet, work...mostly work.

Man

Orange color, long eyelashes. Letter A shape

Those who are weaker than him and easily susceptible to manipulation

Diabetes, loneliness, the prospect of further reforms in the Russian language. Any little thing that a normal person wouldn't worry about. Anxiety can make even the smallest things seem like the end of the world.

Russian language, black humor, nonsense

Lying in bed and trying to drown out fears with sweets and TV series

More than 1000 years